Some motorcycles due to design of the motor cannot completely balance the reciprocating mass inside the motor. To reduce the vibrations, the drivetrain is isolated with flexible couplings made from rubber or other flexible devices. In this context, the drivetrain consists of the motor, transmission, swingarm and a rear drive wheel.
With the drivetrain being suspended by rubber isolators, it can move in directions that cause instability issues, which affect Harley Davidson touring machines and other motorcycle makes and models. This driving instability issue is commonly called “bagger wobble” and is characterized such that when a heavy touring motorcycle is placed in a turn, the entire motorcycle can become unstable, entering a momentary wobbling state. The rubber mount allows the rear wheel to twist or move laterally, thereby upsetting the wheel alignment. This condition can also occur when the motorcycle is operated at high speed in a straight line. The isolation systems fail to hold the rear wheel in proper alignment and an oscillation ensues.
Conceived as a new mechanism for drivetrain isolation, the concept of a rubber mounted drivetrain system was originally developed by Norton Motorcycles in the late 1960's and early 1970's.
Harley-Davidson developed their version of the rubber mounted drivetrain system in the late 1970's. The system utilizes a front rubber isolator and in some versions a link to control lateral movement in the front, a link at the top of the motor to keep the drivetrain upright, and rubber isolation devices at the rear near the transmission and swingarm. The rubber isolators in the back attempt to hold the drivetrain in alignment. Its implementation has remained unchanged until today with the exception of various aftermarket accessories.
Examination of the current aftermarket offerings show that they fall into two categories:                a. They attempt to limit the compression of the rubber isolator by adding a stiff plastic piece or a different isolator all together; or        b. They fasten to a cross member or part of the frame, and utilize a link to control the motorcycle drivetrain side-to-side play.        
Examples of current aftermarket offerings include:                a. Bagger-Brace manufactured by Phoenix Customs;        b. STA-BO swingarm bushing stabilizers. This aftermarket offering is related to US Patent Application 20090208155, titled “Swingarm bushing stabilizer for Harley-Davidson”;        c. Touring Link chassis stabilizer, manufactured by Progressive Suspension;        d. Glide-Pro Stabilizing System;        e. True-Track swingarm pivot anchors. This aftermarket offering is related to U.S. Pat. No. 7,677,348, titled “Apparatus for deterring instability of a motorcycle”.        
Current aftermarket offerings have certain limitations, particularly that they either are simple in design, but do not provide significant added stability, or that they are complex structural components, which are expensive and difficult to install.
As such, considering the foregoing, it may be appreciated that there continues to be a need for novel and improved devices and methods for improving lateral stability of a motorcycle drivetrain system.